This castle was established by the 4th Duke of Montrose and is connected to the Buchanan Clan.

This series of Scottish caves has no clear purpose other than baffling historians.

Islanders once used this dramatic, otherworldly landscape to hide their cattle from Viking raiders.

Now famous as the "Harry Potter bridge," this impressive concrete viaduct has long been an icon in its own right.

An ancient Scottish rock formation said to be the gravesite of a giant remains ensconced in legend and intrigue.

Ancient cliffs resembling a kilt on Scotland's second largest island emit an entrancing sound.

Amazing and mysterious Neolithic settlement on Scotland's Orkney Islands.

Northern Ireland's Brobdingnagian stepping stones.

Ruined 11th century abbey built by King David I in Edinburgh, Scotland.

The atmospheric road was never meant to be so creepy.

The most iconic structure in Scotland has been home to bishops, colonels, and Sean Connery characters.

17th century streets hidden under Edinburgh were once a breeding ground for the black death.

These fantastically named natural pools look like something out of a Scottish myth.

This dramatic landscape hidden on the Isle of Skye looks as though you've stepped into the magical realm.

This astonishingly geometric cave has inspired everyone from Jules Verne to Pink Floyd.

This ornate Victorian marketplace was the setting for Diagon Alley and the Leaky Cauldron in the Harry Potter films.

The pockmarks across the building's facade are remnants of the Blitz.

Some of England's last cave dwellers lived and worked within this huge cave.

This medieval manor house was equipped with secret compartments for hiding priests.

This Norman castle has been the scene of assassination plots, religious persecution, and Nazi conspiracies throughout its long history.

These medieval monastery ruins are surprisingly overlooked by most tourists.

Graffiti from the 16th and 17th centuries cover the walls of this part of the Tower of London.

This giant wooden treehouse within a sprawling garden has its own eatery.

You can crawl inside this atmospheric 5,000-year-old tomb.